Aircraft Communication Systems Flashcards

A dispatcher receives a PIREP via ACARS reporting severe turbulence at FL370. What is the dispatcher's primary obligation?

Answer: Evaluate the report, update the flight release if necessary, and notify the affected crew and other flights in the area

The dispatcher must assess the hazard, update release documentation as needed, and ensure all affected crews receive the safety-relevant information.

Which statement about VDL Mode 2 (VHF Digital Link Mode 2) is correct?

Answer: It is a digital data link standard that replaces analog ACARS on VHF frequencies for higher data rates

VDL Mode 2 is a higher-speed digital data link operating in the VHF band that is replacing older analog ACARS for AOC and ATC datalink communications.

Which federal regulation specifically addresses the requirement for two-way radio communication capability for airplanes operated under Part 121?

Answer: FAR 121.347

FAR 121.347 prescribes the radio communication equipment requirements for air carrier operations under Part 121.

What is the role of a company radio frequency (company frequency) compared to ATC frequencies?

Answer: Company frequencies allow direct communication between flight crews and airline operations/dispatch without ATC involvement

Company frequencies are assigned to specific airlines to allow operational communications between aircraft and dispatch/operations, separate from ATC.

During a volcanic ash event, what communication action should a dispatcher take regarding aircraft near the ash cloud?

Answer: Immediately contact all affected crews via all available means, relay SIGMET information, and update flight releases with avoidance routing

Volcanic ash is an immediate airworthiness hazard; dispatchers must proactively communicate SIGMET data and coordinate avoidance for all potentially affected flights.

Satellite Communication (SATCOM) systems used in aviation primarily rely on which type of satellite constellation for oceanic coverage?

Answer: Geostationary satellites positioned approximately 35,786 km above the equator

Aviation SATCOM (e.g., Inmarsat) primarily uses geostationary satellites, though newer systems like Iridium use LEO constellations for polar coverage.

If an aircraft cannot contact its dispatcher due to a communication failure, under Part 121 the pilot-in-command may:

Answer: Continue the flight and exercise PIC authority, but must re-establish contact and comply with the last clearance received from dispatch

FAR 121.535 allows the PIC to proceed per the last valid dispatch release when communication with dispatch is lost, while making every effort to re-establish contact.